<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Animation Workbench</title>
  <style>
    :root {
      --side-width: 208px;
    }

    body {
      margin: 0;
      height: 100%;
      font-size: 0.75rem;
    }

    .workbench {
      display: flex;
      height: 100%;
    }

    .menu {
      position: absolute;
      inset: 0 auto 0 0;
      z-index: 1;
      display: flex;
      flex-direction: column;
      row-gap: 12px;
      width: var(--side-width);
      padding: 16px;
      background-color: #f5f6f7;
      box-shadow: 0 0 0 1px rgba(0,0,0,.4);
      box-sizing: border-box;
      overflow-y: scroll;
      overflow-x: hidden;
    }

    .menu::-webkit-scrollbar {
      display: none;
    }

    .menu-item {
      appearance: none;
      height: 32px;
      border: none;
      border-radius: 6px; 
      box-shadow: 0 0 0 6px transparent;
      background-color: rgba(0,0,0,.15);
      transition: all .3s;
      outline: none;
    }

    .menu-item:hover {
      background-color: rgba(0,0,0,.2);
    }

    .menu-item:active {
      background-color: rgba(0,0,0,.35);
      box-shadow: 0 0 0 2px #0008;
    }

    .menu-item:focus {
      box-shadow: 0 0 0 2cap #0008;
    }

    .view {
      flex: 1;
      display: grid;
      place-items: center;
      height: 100vh;
      margin-left: var(--side-width);
      overflow: hidden;
    }

    .view > .placeholder {
      font-size: 4rem;
      font-weight: 700;
      opacity: .2;
      color: transparent;
      -webkit-text-stroke-color: rgba(170,170,170,1);
      -webkit-text-stroke-width: 2px;
    }

    .view > iframe {
      width: 100%;
      height: 100%;
      border: none;
    }
  </style>
</head>
<body>
  <script src="workbench.js"></script>
</body>
</html>
